Device for determining settling rates of solids or particulate bearing liquid in a continuous process or flowing stream

ABSTRACT

Apparatus and method for determining the settling rate of solids or particulate bearing liquids in a continuous process or flowing stream in which a sample of the material is periodically selected and placed in a chamber which is transparent or has a transparent portion through which a light beam can pass such that a detector detects the amount of light passing through the chamber and the material and wherein the light transmissivity at various times is recorded and used to calculate the partial settling rate, the full settling rate and the percentage of solids or parts per million in the sample.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to apparatus and method for measuringsettling rates of a solid or particulate bearing liquid in a continuousprocess of a flowing stream.

2. Description of the Prior Art

Present methods for determining the settling rate of solids orparticulate bearing liquid in a continuous process or flowing stream arevery laborious and require a great deal of manual labor. The results ofsuch systems are very inaccurate.

SUMMARY OF THE INVENTION

The present invention comprises apparatus and method of determining thesettling rates of solids or particulate bearing liquids in a continuousprocess of a flowing stream wherein periodically a sample of the liquidis drawn into a transparent chamber through which a light beam is passedand detected after passing through the chamber and the liquid. The lighttransmissivity is measured at a number of different times. The lighttransmissivity of the chamber without liquid in it is also measured. Thefilling and emptying of the chamber is automatically controlled and thereadings of the transmissivity are automatically obtained and storedfrom which storage means the partial settling rate as well as the fullsettling rate and the percentage of solids or part per million in thesystem can be ascertained. Thus, the invention provides an automaticsimple apparatus and method for obtaining these readings.

Other objects, features and advantages of the invention will be readilyapparent from the following description of certain preferred embodimentsthereof taken in conjunction with the accompanying drawings althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts of the disclosure and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the invention; and

FIG. 2 is a block diagram illustrating the calculating portion of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a pipe 10 in which a liquid containing solid orparticulate moves therethrough. A container or chamber 11 is attached tothe pipe 10 and an opening 15 is provided for communication between theinside of pipe 10 and the container 11. A fluid 8 containing solids orparticulate matter moves in pipe 10 and an analyzing chamber 11 isattached to the pipe 10 and communicates therewith with an orifice 15over which a valve 20 is placed such that a piston 14 connected to apiston shaft 16 that extends to the end 17 of the chamber 16 can bemoved to draw a sample of the liquid 8 into the chamber 11. A motor 19is connected to the upper end 18 of the piston shaft 16 for actuatingthe piston 14 up and down in the chamber 11 to withdraw a sample intothe container 11 and to exhaust it from the container 11 through thevalve 20 back into the pipe 10. The walls 12 of the chamber 11 aretransparent or at least a portion of the walls are transparent such thatlight from a light source 21 connected to a suitable power supplythrough terminals 22 and 23 will pass through the chamber 12 and thesample within the chamber to a light detector 24. A plurality ofelectrical storage signal devices 41, 48, 53 and 57 are connected to acommon lead 43 which is connected by lead 46 to one side of the detector24. The other side of the detector 24 is connected to a lead 44 which isconnected to normally open contacts of a plurality of switches 39, 47,51 and 54 mounted about a cam 37 which is driven by shaft 31 connectedto the output of a timing motor 26. The cam 37 has a high portion 38such that when the high portion is aligned with the switch 39 it movesits moveable contact into engagement with a stationary contact so thatlead 44 is connected to lead 42 which is connected to the second side ofthe A storage means 41. The moveable contact of switch 47 when engagedby the high portion 38 of cam 37 connects lead 44 with lead 49 which isconnected to the second side of B storage means 48. The moveable contactof switch 51 engages the fixed contact of the switch when the highportion 38 of cam 37 engages it so as to connect lead 44 to lead 52which is connected to the second side of the C storage means 53. Themoveable contact of switch 54 when engaged by the high portion 38 of cam37 connects lead 44 to lead 56 which is connected to the second side ofthe Z storage 57.

The timing motor 26 also carries a cam 32 with a high portion 33 whichis engageable with motor control switches 35 and 36 to energize themotor 19 which controls the piston 14 in the chamber 11. The powersupply 34 has one side 81 connected to the motor 19 and a pair ofoutputs 82 and 83, respectively connected to fixed terminals of switches35 and 36. The moveable contact of switch 35 is connected to lead 83which is connected to the motor 19 when the switch 35 is closed and thelead 86 and lead 83 are electrically connected together such that thepower supply 34 supplies power to the motor 19 to drive it in a firstdirection as, for example, to cause the piston 14 to move up in thechamber 11 to draw a sample from pipe 10 into the chamber 11. The switch36 when closed by the high portion 33 of cam 32 connects power supplylead 82 to motor lead 84 so as to cause the motor 19 to drive in theopposite direction so as to move the piston 14 downwardly in the chamber11 to eject the sample fluid back into the pipe 10.

The cams 32 and 37 are positioned on shaft 31 such that the highportions 33 and 38 of the cams 32 and 37, respectively, actuate thepiston 14 and cause the light detector 24 to be connected to the storagemeans 41, 48, 53 and 57 in a sequence such that the first storage meansreceives a signal at time T0 which is very shortly after the container11 has been filled with the sample fluid. The storage means 48 isconnected by the switch 47 to the detector 24 at a subsequent time T1which might, for example, be 30 seconds after the container 11 has beenfilled with sample material and during which time certain amount ofsettling of the particulate matter and solids will have occured so thatmore light will pass through the fluid at time T1 than it did at timeT0. The storage means 53 is connected to the sampler 24 at a subsequenttime T2 and the Z storage 57 is connected to the detector 24 after theplunger 14 has ejected the fluid from the chamber 11 and the detector 24detects the light energy at a time when there is no fluid in thecontainer. For this purpose, an opening 85 may be formed in the pistonrod 16 so as to allow the light to pass from the light source 21 to thedetector 24 when the piston 14 is in the down position illustrated inFIG. 1.

The detector 24 may be a photosensitive cell which produces anelectrical output indicative of the amount of light energy whichimpinges upon it and this, of course, varies depending on thetransmissivity of the container 11 and fluid contained in the container11.

The sequence of operation is as follows:

1. The switch 27 is closed to start the sequence connecting power frompower terminals 28 and 29 to timing motor 26 so that it starts anddrives shaft 31 thus moving cams 32 and 37.

2. The sample is drawn into container 11 by the piston 14.

3. The light transmissivity is measured at time T0 (time 0) and isrestored and held in the A storage 41. Reading A

4. A waiting period of precise time as for 0 to 30 seconds occurs.

5. The transmissivity is again measured and recorded and held in thestorage 48. Time - T1, reading B

6. Wait a precise time as, for example, 0-60 seconds, at time T2.

7. Measure the transmissivity and store in the C storage 53.

8. Energize motor 19 so as to exhaust the sample from the container 11.

9. Read light transmissivity for calibration purposes with the containerempty and store in Z storage 57. Z reading

The cycle continues as long as switch 27 is closed.

The partial settling rate can be calculated as follows:

    Partial settling rate=A-B/T.sub.1

The full settling rate can be calculated as follows:

    Full settling rate=A-C/T.sub.2

The percentage solids or parts per million in the system can becalculated as A-Z.

These calculations can be performed with the apparatus illustrated inFIG. 2. The A storage 41 which retains the electrical signalproportional to the transmissivity at time T₀ when the sample is firstplaced into the chamber 11 is supplied to a subtraction circuit 58 whichalso receives an output from the B storage 48 in which thetransmissivity of the sample and the container 11 has been measured at atime T₁ which might be approximately 30 seconds after time T₀. Theoutput of the subtraction circuit 58 is equal to A-B and this signal issupplied to a divider 59 which receives an input signal proportional tothe time T₁ from a generator 61 which can be set manually or otherwiseby a knob 65 to the time difference between the first transmissivitymeasurement which is supplied to A storage means 41 and the secondtransmissivity measurement which is supplied to B storage means 48. Theelectrical signal from the time generator 61 is supplied to the divider59 wherein it is divided into the signals A-B and this output issupplied to a meter 62 which indicates in its indicating portion 63 thepartial settling rate of the solids or particulate in the sample in thecontainer 11.

A subtraction circuit 65 also receives the output of the A storage 41 aswell as an output from the C storage means 53 and subtracts C from A toproduce an output signal A-C. A time generator 66 can be set by a knob70 to time T₂ which is the time of the taking of the transmissivitywhich is supplied to the C storage 53 and which might be in the range of60 seconds. A divider 64 receives the output of the subtraction circuit65 and the output of the time generator 66 and the signal A-C is dividedby the time signal T₂ and the output is supplied to an indicator 67which has an indicating portion 68 wherein the full settling rate of thesolids or particulate in the sample in the chamber 11 is indicated.

The output of the Z storage 57 is supplied to a subtraction circuit 69which also receives an output from the A storage means 41 and the outputof the subtraction circuit 69 produce a signal A-Z which is supplied toan indicator 71 that has an indicating portion 72 that indicates thepercentage solids or part per million in the sample and the container11.

It is seen that the present invention provides automatic simple meansfor calculating a partial settling rate, the full settling rate and thepercentage of solids or part per million in the system and although theinvention has been described with respect to preferred embodiments, itis not to be so limited as changes and modifications can be made thereinwhich are within the full intended scope of the invention as defined bythe appended claims.

I claim as my invention:
 1. Apparatus for determining the settling ratesof solids or particulate in moving liquid comprising a container fluidlycommunicating with said moving liquid, means for filing and emptyingsaid container, motor means for controlling said filing and emptyingmeans, transparent portions of side walls of said container, a lightsource mounted on one side of said container adjacent one of saidtransparent portions, a light sensor mounted on the opposite of saidcontainer adjacent the other transparent portion to measure lighttransmissivity, a timing motor connected to said motor means to cause itto fill and empty said container, a switch means connected to saidtiming motor and having a plurality of switches which are closed atdifferent times by said timing motor, one side of said light sensorconnected to one terminal of each of said plurality of switches, aplurality of storage means with first input terminals connected to theother side of said light sensor, a second terminal of each of saidplurality of switches respectively connected to second input terminalsof each of said plurality of storage means, a first subtractor receivinginput signals from a first and a second of said plurality of storagemeans and subtracting said signals, a first time signal generatorsupplying an output signal proportional to the difference in times whenthe transmissivity signals were supplied to said first and secondstorage means, a first divider receiving the outputs of said firstsubtractor and said first time signal generator and dividing thesubtractor signal by the time signal, and a first indicator receivingthe output of said first divider to indicate the settling rate. 2.Apparatus according to claim 1 wherein said timing motor includes a pairof cams which engage said plurality of switches to open and close themin a predetermined sequence.
 3. Apparatus according to claim 1 includingsecond subtractor means receiving input signals from said first and athird of said plurality of storage means and subtracting said signals, asecond time signal generator supplying an output signal proportional tothe difference in times between when the transmissivity signals wheresupplied to said first and third storage means, a second dividerreceiving the outputs of said second subtractor and said second timesignal generator and dividing the subtractor signal by the time signal,and a second indicator receiving the output of said second divider toindicate the final settling rate.
 4. Apparatus for determining thesettling rates of solids or particulate in liquid, comprising acontainer in which a sample of said liquid can be held, a means formeasuring to obtain a light transmissivity signal of said sample at afirst time, a timing means connected to said means for measuring toobtain a light transmissivity of said sample at a second time, means forcalculating the settling rate of solids connected to said means formeasuring, wherein said container is transparent to light energy andsaid means for calculating includes first means for storing said lighttransmissivity signal at said first time, wherein said means forcalculating includes second means for storing said light transmissivitysignal at said second time, a subtractor connected to said first andsecond storage means, a time signal generator for producing a signalproportional to the time difference between said first and second times,a divider means receiving the outputs of said subtractor and said timesignal generator and dividing the time signal generator signal into thesignal from said subtractor and indicator means receiving the output ofsaid divider means to indicate the settling rate, wherein said measuringmeans includes a light source mounted on one side of said container anda light detector mounted on the other side of said container, whereinsaid timing means controls said measuring means to obtain a lighttransmissivity signal of said sample at a third time, and saidcalculating means includes a third storing means for storing said lighttransmissivity signal at said third time, a second time signal generatorfor producing a signal proportional to the time difference between saidfirst and third times, a second subtractor connected to said first andsecond storage means and producing a difference signal, a second dividermeans receiving inputs from said second subtractor and said second timesignal generator and dividing the second time generator signal into theoutput of said second subtractor and second indicator means connected tothe output of said second divider means and indicating a full settlingrate, and including a fourth storing means for storing a lighttransmissivity signal when there is no sample in said container, a thirdsubtractor receiving inputs from said first and fourth storage means andproducing a difference signal, and a third indicator connected to saidthird subtractor and indicating the percentage of solids or parts permillion of solids.
 5. Apparatus for determining the settling rates ofsolids or particulate in liquid, comprising a container in which asample of said liquid can be held, a means for measuring to obtain alight transmissivity signal of said sample at a first time, a timingmeans connected to said means for measuring to obtain a lighttransmissivity of said sample at a second time, means for calculatingthe settling rate of solids connected to said means for measuring,wherein said container is transparent to light energy and said means forcalculating includes first means for storing said light transmissivitysignal at said first time, and wherein said means for calculatingincludes second means for storing said light transmissivity signal atsaid second time, a subtractor connected to said first and secondstorage means, a time signal generator for producing a signalproportional to the time difference between said first and second times,a divider means receiving the outputs of said subtractor and said timesignal generator and dividing the time signal generator signal into thesignal from said subtractor and indicator means receiving the output ofsaid divider means to indicate the settling rate, wherein said measuringmeans includes a light source mounted on one side of said container anda light detector mounted on the other side of said container, saidtiming means controlling said measuring means to obtain a lighttransmissivity signal of said sample at a third time, and saidcalculating means including a third storing means for storing said lighttransmissivity signal at said third time, a second time signal generatorfor producing a signal proportional to the time difference between saidfirst and third times, a second subtractor connected to said first andsecond storage means and producing a difference signal, a second dividermeans receiving inputs from said second subtractor and said second timesignal generator and dividing the second time generator signal into theoutput of said second subtractor and second indicator means connected tothe output of said second divider means and indicating a full settlingrate.
 6. Apparatus for determining the settling rates of solids orparticulate in liquid, comprising a container in which a sample of saidliquid can be held, a means for measuring to obtain a lighttransmissivity signal of said sample at a first time, a timing meansconnected to said means for measuring to obtain a light transmissivityof said sample at a second time, means for calculating the settling rateof solids connected to said means for measuring, wherein said containeris transparent to light energy and said means for calculating includesfirst means for storing said light transmissivity signal at said firsttime, and wherein said means for calculating includes second means forstoring said light transmissivity signal at said second time, asubtractor connected to said first and second storage means, a timesignal generator for producing a signal proportional to the timedifference between said first and second times, a divider meansreceiving the outputs of said subtractor and said time signal generatorand dividing the time signal generator signal into the signal from saidsubtractor and indicator means receiving the output of said dividermeans to indicate the settling rate, and wherein said measuring meansincludes a light source mounted on one side of said container and alight detector mounted on the other side of said container.